1. Field of the Invention
The subject invention generally pertains to a system for restraining a vehicle at a loading dock, and more specifically to a vehicle restraint that is wheel-actuated.
2. Description of Related Art
In the loading and unloading of vehicles at a loading dock, heavy equipment such as forklifts pass into and out of the vehicle to facilitate and expedite the unloading and/or loading of the vehicle. Accordingly, it is important that the vehicle remain generally fixed relative to the loading dock to avoid accidents and to protect the safety of dock personnel. Otherwise, there is a potential hazard for the vehicle to inadvertently move away from the loading dock during the loading/unloading operation. If this were to occur without the knowledge of the dock personnel, they could continue to attempt to move cargo into or out of the vehicle while assuming the vehicle is secured at the dock. Thus, injury to personnel or damage to dock equipment could occur.
A common method of restraining a vehicle at a loading dock involves manually wedging wheel chocks in front of a vehicle""s wheels. The use of wheel chocks, however, have several drawbacks: 1) the blocks are easily lost or damaged; 2) the blocks may not operate effectively due to a slippery road surface from oil, grit, rain, ice, or snow; 3) wheel chocks are awkward to handle and sometimes difficult to remove from the wedged position; 4) vehicles have been known to drive over wheel chocks; and 5) manually reaching underneath a vehicle (to insert or remove chocks) is inherently hazardous.
Given the potential hazards of such manual placement of wheel chocks, automated chocking systems have been employed. While such systems are safer and more convenient than manual positioning of chocks, they may have their own disadvantages. For example, such systems may not be suitable for some vehicles, because the vehicle""s undercarriage, tailgate lifts, mud flaps or adjacent tires, may interfere with the movement of the chock as the chock attempts to engage the wheel. In addition, automated chocking systems may not be adjustable to accommodate the large range of tire sizes on cargo vehicles. Such systems may also be awkward, difficult and time consuming to engage and disengage from the vehicle parked at the dock.
To overcome the disadvantages of these earlier automated chocking devices, improved automated chocking systems are disclosed in U. S. Pat. Nos. 5,762,459 and 5,582,498 and in co-pending application Ser. No. 09/477,264; all of which are expressly incorporated by reference herein. The disclosure of the present invention provides further improvements and enhancements to the designs of the incorporated references.
In some embodiments, a vehicle restraint includes a latching member that engages an inverted gear rack whose gear teeth point downward to prevent dirt and ice from accumulating between the gear teeth.
In some embodiments, a vehicle restraint includes an upper rail with a contoured leading edge for smoothly guiding a wheel-blocking barrier from a stored position to an elevated wheel-chocking position.
In some embodiments, a wheel support helps prevent a low hanging mud flap from getting pinched between a trigger assembly of the vehicle restraint and the vehicle""s wheel.
In some embodiments, a tooth alignment device helps align the teeth of a latching member to that of a gear rack.
In some embodiments, the tooth alignment device includes a movable alignment tooth that is offset relative to the pitch spacing of other teeth.
In some embodiments, the alignment tooth is spring loaded to protrude beyond adjacent teeth.
In some embodiments, the components of a vehicle restraint are arranged to avoid developing on the vehicle restraint""s frame a bending moment that may otherwise exist as a latching member engages a gear rack.